dot-extract

Extracts properties from an object according to a set of dot-delimited field specification strings while preserving the structure of the input object.

API

extract(input, specifications)

Extracts fields from input based on the specification strings.

• input is an object or an array of objects from which to extract fields
• specifications is an array of strings that specify which fields should be extracted

If input is an array, an array of transformed objects will be returned. Otherwise, the transformed object is returned.

Make use of the input array overload to avoid unnecessarily preprocessing the specifications multiple times.

Example

const extract = require('dot-extract')
const assert = require('assert')

const input = {
  name: {
    first: 'Foo',
    initial: 'X',
    last: 'Bar',
  },
  pets: [
    {
      name: 'Doggy',
      type: 'dog',
      age: 2,
    },
    {
      name: 'Kitty',
      type: 'cat',
      age: 5,
    },
  ],
}

const specification = [
  'name.first',
  'name.last',
  'pets.name',
]

const actual = extract(input, specification)

const expected = {
  name: {
    first: 'Foo',
    last: 'Bar',
  },
  pets: [
    {
      name: 'Doggy',
    },
    {
      name: 'Kitty',
    },
  ],
}

assert.deepStrictEqual(actual, expected)